A method for reducing bacterial enteropathogens in fowl subjected to feed withdrawal is disclosed which involves withdrawing feed from fowl and orally administering to the fowl an effective amount of a cocktail sufficient to reduce bacterial enteropathogens in the crop of the fowl, wherein the cocktail contains water, a carbohydrate, and optionally a protein source, a vitamin source, an organic acid, an emulsifier, a mineral source, and mixtures thereof.
The contamination of broiler carcasses with human enteropathogens remains a problem in the broiler industry. The crop is one of the reservoirs for Salmonella and other Enterobacteriaceae in broiler chickens subjected to feed withdrawal (Hargis, B. M., et al., Poultry Sci., 74:1548-1552 (1995); Hinton, A., Jr., et al., xe2x80x9cPhysical, chemical, and microbiological changes in the crop of broiler chickens subjected to incremental feed withdrawalxe2x80x9d, Poultry Sci., 79:212-218 (1999)). Broilers are subjected to feed withdrawal to reduce the potential for spreading ingesta and fecal material between live animals during transport and between carcasses during processing (Wabeck, C. J., Poultry Sci., 51:1119-1121 (1972)). During feed withdrawal poultry farmers deny their animals access to feed immediately before shipping the animals to processing plants. Feed withdrawal is effective because it facilitates the emptying of the crop and other portions of the alimentary tract of the animals before the animals are placed on transport trucks.
However, one of the undesirable effects of feed withdrawal is that the natural ability of the crop to inhibit the growth of Salmonellae and other Enterobacteriaceae is reduced when the animals are denied access to feed (Ramirez, G. A., et al., Poultry Sci., 76:654-656 (1997); Hinton, A., Jr., et al., Poultry Sci., 79:212-218 (1999)). In full fed broilers, fermentation of feed in the crop creates conditions that inhibit the growth of Enterobacteriaceae (Hinton, A., Jr., et al., J. Food Prot., 55:162-166 (1992)). The decrease in the anti-Enterobacteriaceae activity of the crop during feed withdrawal is related to decreases in the crop""s population of lactic acid bacteria, increases in the pH of the contents of the crop, and decreases in the concentration of acetic, propionic, and lactic acid in the crop as it is emptied of feed (Hinton, A., Jr., et al., Poultry Sci., 79:212-218 (1999); Hinton, A., Jr., et al., xe2x80x9cChanges in the concentration of metabolic intermediates in the crop of poultry subjected to feed withdrawalxe2x80x9d, Annual Meeting of the Poultry Science Society, Poultry Sci., 78 (Suppl. 1):27 (Abstr.)(1999)).
We have discovered that providing fowl (e.g., broilers) a cocktail (containing water and a carbohydrate, for example, glucose or sucrose) while they are denied access to feed reduces the number of bacterial enteropathogens present in the crop.
A method for reducing bacterial enteropathogens in fowl subjected to feed withdrawal, involving withdrawing feed from fowl and orally administering to the fowl an effective amount of a cocktail sufficient to reduce bacterial enteropathogens in the crop of the fowl, wherein the cocktail contains water, a carbohydrate, and optionally a protein source, a vitamin source, an organic acid, an emulsifier, a mineral source, and mixtures thereof.
One aspect of the present invention involves a method for reducing bacterial enteropathogens in fowl subjected to feed withdrawal, involving withdrawing feed from fowl and orally administering to the fowl a bacterial enteropathogen reducing effective amount of a cocktail (sufficient to reduce bacterial enteropathogens in the crop of said fowl), wherein the cocktail contains water, a carbohydrate, and optionally a protein source, a vitamin source, an organic acid or inorganic acid, an emulsifier, a mineral source, and mixtures thereof.
Bacterial enteropathogens include members of the Enterobacteriaceae family (e.g., salmonellae such as Salmonella typhimurium) and Campylobacter species (e.g., Campylobacter jejuni or coli).
The cocktail contains water, carbohydrates, and optionally other ingredients. The carbohydrate may be any carbohydrate effective in substantially reducing bacterial enteropathogens in the crops of fowl (e.g., broiler chickens) subjected to feed withdrawal (reduction in bacterial enteropathogens in comparison with untreated fowl). Such carbohydrates, which must be biologically acceptable to fowl, include monosaccharides (e.g., glucose, fructose, mannose, galactose), disaccharides (e.g., sucrose, maltose, lactose, cellobiose), and polysaccharides (e.g., starch, amylose, glycogen, dextrins).
The cocktail is administered in an amount effective to substantially reduce bacterial enteropathogens in the crops of fowl (e.g., broiler chickens) subjected to feed withdrawal (reduction in bacterial enteropathogens in comparison with untreated fowl). The effective amount of the carbohydrate in the cocktail may be readily determined by the practioner skilled in the art by following the procedures utilized below. Generally, the effective concentration of the carbohydrate is that which results in a substantial reduction in bacterial enteropathogens (e.g., Salmonella and/or other Enterobacteriaceae, and optionally Campylobacter) in the crop. For example, the cocktail may contain about 6% to about 15% (e.g., 6%-15%) glucose, preferably about 7% to about 12% (e.g., 7%-12%) glucose, more preferably about 7% to about 10% glucose (e.g., 7%-10%), most preferably about 7.5% (e.g., 7.5%) glucose, or about 1% to about 20% (e.g., 1%-20%) sucrose, preferably about 2% to about 15% (e.g., 2%-15%) sucrose, more preferably about 4% to about 10% sucrose (e.g., 4%-10%).
The optional other ingredients generally include 1-20 g/l of a protein source (e.g., enzymatically hydrolyzed protein), 1-10 g/l of a vitamin source (e.g., autolyzed yeast), 0.5-10 g/l of an organic acid (e.g., tricarboxylic acid cycle acids such as fumaric acid; without being bound by theory, the organic acid may allow the cocktail to reduce harmful bacteria in the ceca (lower intestinal tract)) or inorganic acid (e.g., phosphoric acid), 1-5 g/l of an emulsifier (e.g., polyoxyethylenesorbitans), and 0.1-1 g/l of a mineral source (e.g., magnesium salts, maganese salts). For example the cocktails may contain proteose peptone (Difco Laboratories, Detroit, Mich.); beef extract (Sigma Chemical Co., St. Louis, Mo.); yeast extract (Difco Laboratories, Detroit, Mich.); fumaric acid (Sigma Chemical Co., St. Louis, Mo.); polyoxyethylene-sorbitan monooleate (Tween 80)(Sigma Chemica Co., St. Louis, Mo.); magnesium sulfate, heptahydrate (Sigma Chemica Co., St. Louis, Mo.); and manganese sulfate, monohydrate (Sigma Chemica Co., St. Louis, Mo.). Generally the pH of the cocktails is adjusted to 6.0 with a solution of propionic acid and glacial acetic acid. The cocktails generally are autoclaved at about 121xc2x0 C. for about 15 min then stored at about 4xc2x0 C. until ready for use. The cocktail may also include metabolic intermediates such as organic acids (e.g., fumaric acid (about 0.01%-about 0.2%), malic acid (about 0.01%-about 0.2%)) or inorganic acids (e.g., phosphoric acid).
The fowl (e.g., poultry such as chickens, turkeys, ducks, quail, and geese) are denied access to the feed for 6 to 48 hours before being processed. Fowl will be given access to the cocktail zero to four hours before feed is withdrawn and will have continual access to the cocktail throughout the feed withdrawal period. The cocktail may also be administered to fowl not subjected to feed withdrawal or it may be administered to fowl that are temporarily subjected to feed withdrawal. Generally, the water supply is replaced by the cocktail.